Hysterectomy is the most common non-pregnancy related surgical procedure in U.S. women with approximately 600,000 performed annually. The number of bilateral salpingo-oophorectomies performed with hysterectomies has doubled from 25% in 1965 to 55% in 1999. Clearly, the fact that prophylactic bilateral salpingo-oophorectomies prevent ovarian cancer plays a significant factor in this decision process, as epithelial ovarian cancer is the leading cause of mortality from gynecologic cancers in the U.S. However, ovaries secrete hormones that can potentially provide many health benefits, including prevention of osteoporosis and coronary heart disease. Since many women undergo hysterectomies annually, the health and economic consequences of removing ovaries needs further investigation. However, given the long interval between oophorectomy and subsequent health outcomes, it is unlikely that this question will ever be addressed in a large, prospective randomized trial. The objectives of this project are to describe practice patterns of prophylactic salpingo-oophorectomy among women undergoing hysterectomy for benign conditions and to estimate the age-specific rates of ovarian cancer and adnexal surgery after ovarian preservation. The study will be conducted among female members of Kaiser Permanente membership. Electronic medical records will be used to identify a cohort of approximately 120,000 women undergoing hysterectomy for benign conditions from 1979-2006, and identify those undergoing hysterectomy alone, as well as hysterectomy plus oophorectomy. This pilot study will enable us to establish a well-characterized patient cohort and to examine the feasibility of conducting a comprehensive study to evaluate the health-related effects of prophylactic salpingo- oophorectomy including breast cancer, colon cancer, ovarian cancer, cardiovascular and cerebrovascular disease, and osteoporosis. This research could have considerable public health impact since over half a million women undergo hysterectomies each year, and these results could help physicians and patients to decide whether the health benefits of removing ovaries outweigh the associated risks, and if so, at what age. PUBLIC HEALTH RELEVANCE: The objectives of this project are to describe practice patterns of prophylactic salpingo-oophorectomy among women undergoing hysterectomy for benign conditions and to estimate the age-specific rates of ovarian cancer and adnexal surgery after ovarian preservation. In addition, we will establish a patient cohort for a future, more comprehensive, risk-benefit study of prophylactic salpingo-oophorectomy that will include several other important outcomes such as breast cancer, colon cancer, ovarian cancer, cardiovascular and cerebrovascular disease, and osteoporosis. This research will have considerable public health impact since over half a million women undergo hysterectomies each year and these results could help physicians and patients to decide whether the health benefits of removing ovaries outweigh the associated risks, and if so, at what age. [unreadable] [unreadable] [unreadable]